Methods, apparatuses, and computer programs for providing a flexible frequency location for a backwards compatible carrier in a communication system are provided. Embodiments of the invention enable a backwards compatible carrier segment supporting all or a subset of legacy LTE Release transmission modes to be located at an arbitrary position on the system bandwidth (BW) through a cyclic extension of reference signals, such as channel state information reference signals (CSI-RS), and/or other resource element configurations, such as interference measurement reference signals (IMRS), required for supporting PDSCH operation outside the backwards compatible carrier segment.